#ifndef H_VECT_INCLUDED

#define H_VECT_INCLUDED

#ifdef __cplusplus

extern "C" {

typedef struct {

double x;

double y;

} vec_t;

typedef struct {

// order matches SVG transform matrix!

double a, c, e;

double b, d, f;

// 0 0 1 implied!

} mtx_t;

#define VEC(X,Y) ((vec_t){(X),(Y)})

#define MTX(A,C,E,B,D,F) ((mtx_t){(A),(C),(E),(B),(D),(F)})

#define VEC_ZERO VEC( 0, 0 )

#define MTX_ZERO MTX( 0, 0, 0, \

0, 0, 0 )

#define MTX_UNI MTX( 1, 0, 0, \

0, 1, 0 )

vec_t vec_add( vec_t u, vec_t v );

vec_t vec_sub( vec_t u, vec_t v );

vec_t vec_scal( vec_t u, double f );

vec_t vec_mmul( mtx_t m, vec_t v );

vec_t vec_norm( vec_t v, int dir );

double vec_abs( vec_t v );

double vec_dot( vec_t u, vec_t v ); // vector dot (scalar) product

double vec_ang( vec_t u, vec_t v );

int vec_eq( vec_t u, vec_t v, double e );

mtx_t mtx_mmul( mtx_t m, mtx_t n );

#ifdef __cplusplus

}